1 /* 2 ** $Id: lopcodes.h,v 1.142 2011/07/15 12:50:29 roberto Exp $ 3 ** Opcodes for Lua virtual machine 4 ** See Copyright Notice in lua.h 5 */ 6 7 #ifndef lopcodes_h 8 #define lopcodes_h 9 10 #include "llimits.h" 11 12 13 /*=========================================================================== 14 We assume that instructions are unsigned numbers. 15 All instructions have an opcode in the first 6 bits. 16 Instructions can have the following fields: 17 `A' : 8 bits 18 `B' : 9 bits 19 `C' : 9 bits 20 'Ax' : 26 bits ('A', 'B', and 'C' together) 21 `Bx' : 18 bits (`B' and `C' together) 22 `sBx' : signed Bx 23 24 A signed argument is represented in excess K; that is, the number 25 value is the unsigned value minus K. K is exactly the maximum value 26 for that argument (so that -max is represented by 0, and +max is 27 represented by 2*max), which is half the maximum for the corresponding 28 unsigned argument. 29 ===========================================================================*/ 30 31 32 enum OpMode {iABC, iABx, iAsBx, iAx}; /* basic instruction format */ 33 34 35 /* 36 ** size and position of opcode arguments. 37 */ 38 #define SIZE_C 9 39 #define SIZE_B 9 40 #define SIZE_Bx (SIZE_C + SIZE_B) 41 #define SIZE_A 8 42 #define SIZE_Ax (SIZE_C + SIZE_B + SIZE_A) 43 44 #define SIZE_OP 6 45 46 #define POS_OP 0 47 #define POS_A (POS_OP + SIZE_OP) 48 #define POS_C (POS_A + SIZE_A) 49 #define POS_B (POS_C + SIZE_C) 50 #define POS_Bx POS_C 51 #define POS_Ax POS_A 52 53 54 /* 55 ** limits for opcode arguments. 56 ** we use (signed) int to manipulate most arguments, 57 ** so they must fit in LUAI_BITSINT-1 bits (-1 for sign) 58 */ 59 #if SIZE_Bx < LUAI_BITSINT-1 60 #define MAXARG_Bx ((1<<SIZE_Bx)-1) 61 #define MAXARG_sBx (MAXARG_Bx>>1) /* `sBx' is signed */ 62 #else 63 #define MAXARG_Bx MAX_INT 64 #define MAXARG_sBx MAX_INT 65 #endif 66 67 #if SIZE_Ax < LUAI_BITSINT-1 68 #define MAXARG_Ax ((1<<SIZE_Ax)-1) 69 #else 70 #define MAXARG_Ax MAX_INT 71 #endif 72 73 74 #define MAXARG_A ((1<<SIZE_A)-1) 75 #define MAXARG_B ((1<<SIZE_B)-1) 76 #define MAXARG_C ((1<<SIZE_C)-1) 77 78 79 /* creates a mask with `n' 1 bits at position `p' */ 80 #define MASK1(n,p) ((~((~(Instruction)0)<<(n)))<<(p)) 81 82 /* creates a mask with `n' 0 bits at position `p' */ 83 #define MASK0(n,p) (~MASK1(n,p)) 84 85 /* 86 ** the following macros help to manipulate instructions 87 */ 88 89 #define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) 90 #define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ 91 ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP)))) 92 93 #define getarg(i,pos,size) (cast(int, ((i)>>pos) & MASK1(size,0))) 94 #define setarg(i,v,pos,size) ((i) = (((i)&MASK0(size,pos)) | \ 95 ((cast(Instruction, v)<<pos)&MASK1(size,pos)))) 96 97 #define GETARG_A(i) getarg(i, POS_A, SIZE_A) 98 #define SETARG_A(i,v) setarg(i, v, POS_A, SIZE_A) 99 100 #define GETARG_B(i) getarg(i, POS_B, SIZE_B) 101 #define SETARG_B(i,v) setarg(i, v, POS_B, SIZE_B) 102 103 #define GETARG_C(i) getarg(i, POS_C, SIZE_C) 104 #define SETARG_C(i,v) setarg(i, v, POS_C, SIZE_C) 105 106 #define GETARG_Bx(i) getarg(i, POS_Bx, SIZE_Bx) 107 #define SETARG_Bx(i,v) setarg(i, v, POS_Bx, SIZE_Bx) 108 109 #define GETARG_Ax(i) getarg(i, POS_Ax, SIZE_Ax) 110 #define SETARG_Ax(i,v) setarg(i, v, POS_Ax, SIZE_Ax) 111 112 #define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx) 113 #define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx)) 114 115 116 #define CREATE_ABC(o,a,b,c) ((cast(Instruction, o)<<POS_OP) \ 117 | (cast(Instruction, a)<<POS_A) \ 118 | (cast(Instruction, b)<<POS_B) \ 119 | (cast(Instruction, c)<<POS_C)) 120 121 #define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \ 122 | (cast(Instruction, a)<<POS_A) \ 123 | (cast(Instruction, bc)<<POS_Bx)) 124 125 #define CREATE_Ax(o,a) ((cast(Instruction, o)<<POS_OP) \ 126 | (cast(Instruction, a)<<POS_Ax)) 127 128 129 /* 130 ** Macros to operate RK indices 131 */ 132 133 /* this bit 1 means constant (0 means register) */ 134 #define BITRK (1 << (SIZE_B - 1)) 135 136 /* test whether value is a constant */ 137 #define ISK(x) ((x) & BITRK) 138 139 /* gets the index of the constant */ 140 #define INDEXK(r) ((int)(r) & ~BITRK) 141 142 #define MAXINDEXRK (BITRK - 1) 143 144 /* code a constant index as a RK value */ 145 #define RKASK(x) ((x) | BITRK) 146 147 148 /* 149 ** invalid register that fits in 8 bits 150 */ 151 #define NO_REG MAXARG_A 152 153 154 /* 155 ** R(x) - register 156 ** Kst(x) - constant (in constant table) 157 ** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x) 158 */ 159 160 161 /* 162 ** grep "ORDER OP" if you change these enums 163 */ 164 165 typedef enum { 166 /*---------------------------------------------------------------------- 167 name args description 168 ------------------------------------------------------------------------*/ 169 OP_MOVE,/* A B R(A) := R(B) */ 170 OP_LOADK,/* A Bx R(A) := Kst(Bx) */ 171 OP_LOADKX,/* A R(A) := Kst(extra arg) */ 172 OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ 173 OP_LOADNIL,/* A B R(A), R(A+1), ..., R(A+B) := nil */ 174 OP_GETUPVAL,/* A B R(A) := UpValue[B] */ 175 176 OP_GETTABUP,/* A B C R(A) := UpValue[B][RK(C)] */ 177 OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ 178 179 OP_SETTABUP,/* A B C UpValue[A][RK(B)] := RK(C) */ 180 OP_SETUPVAL,/* A B UpValue[B] := R(A) */ 181 OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ 182 183 OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ 184 185 OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ 186 187 OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ 188 OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ 189 OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ 190 OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ 191 OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ 192 OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ 193 OP_UNM,/* A B R(A) := -R(B) */ 194 OP_NOT,/* A B R(A) := not R(B) */ 195 OP_LEN,/* A B R(A) := length of R(B) */ 196 197 OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ 198 199 OP_JMP,/* A sBx pc+=sBx; if (A) close all upvalues >= R(A) + 1 */ 200 OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ 201 OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ 202 OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ 203 204 OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ 205 OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ 206 207 OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ 208 OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ 209 OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ 210 211 OP_FORLOOP,/* A sBx R(A)+=R(A+2); 212 if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ 213 OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ 214 215 OP_TFORCALL,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); */ 216 OP_TFORLOOP,/* A sBx if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/ 217 218 OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ 219 220 OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx]) */ 221 222 OP_VARARG,/* A B R(A), R(A+1), ..., R(A+B-2) = vararg */ 223 224 OP_EXTRAARG/* Ax extra (larger) argument for previous opcode */ 225 } OpCode; 226 227 228 #define NUM_OPCODES (cast(int, OP_EXTRAARG) + 1) 229 230 231 232 /*=========================================================================== 233 Notes: 234 (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then `top' is 235 set to last_result+1, so next open instruction (OP_CALL, OP_RETURN, 236 OP_SETLIST) may use `top'. 237 238 (*) In OP_VARARG, if (B == 0) then use actual number of varargs and 239 set top (like in OP_CALL with C == 0). 240 241 (*) In OP_RETURN, if (B == 0) then return up to `top'. 242 243 (*) In OP_SETLIST, if (B == 0) then B = `top'; if (C == 0) then next 244 'instruction' is EXTRAARG(real C). 245 246 (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG. 247 248 (*) For comparisons, A specifies what condition the test should accept 249 (true or false). 250 251 (*) All `skips' (pc++) assume that next instruction is a jump. 252 253 ===========================================================================*/ 254 255 256 /* 257 ** masks for instruction properties. The format is: 258 ** bits 0-1: op mode 259 ** bits 2-3: C arg mode 260 ** bits 4-5: B arg mode 261 ** bit 6: instruction set register A 262 ** bit 7: operator is a test (next instruction must be a jump) 263 */ 264 265 enum OpArgMask { 266 OpArgN, /* argument is not used */ 267 OpArgU, /* argument is used */ 268 OpArgR, /* argument is a register or a jump offset */ 269 OpArgK /* argument is a constant or register/constant */ 270 }; 271 272 LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES]; 273 274 #define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3)) 275 #define getBMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3)) 276 #define getCMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3)) 277 #define testAMode(m) (luaP_opmodes[m] & (1 << 6)) 278 #define testTMode(m) (luaP_opmodes[m] & (1 << 7)) 279 280 281 LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1]; /* opcode names */ 282 283 284 /* number of list items to accumulate before a SETLIST instruction */ 285 #define LFIELDS_PER_FLUSH 50 286 287 288 #endif 289